Telescope.



No. 880,028. PATENTED FEB. 25, 1908.

A. mime. TELESGOPE.

APPLICATION FILED MAY 25, 1907.

EW @2 Hw ALBERT KNIG, or JENA, GERMANY,

AssieNoa To THE FIRM or CARL zeiss, or JENA,

GERMANY.

TELESCOPE No. sso,o2e.

Specification of Letters Patent.

Patented Feb. 25, 1808.

Application led May 25. 1907. Serial No. 315.605.

To all whom it may concern:

Be it known that i, ALBERT KNIG, doctor of philosophy, a citizen of the. German Empire, and residing at Carl-Zeiss strasse, Jena, in the Grand Duchy of SziXc-vlf'ciinaiy Germany, have invented a new and useful Telescope, of which the following is .a specilication. Y

in the use of a terrestrial telescope the observer often wishes, that the field of view might be extended further in one direction, for example, in the horizontal direction, while at the same time he is aware, that the extent of the field of view in the direction at right angles tothe iirst is greater than is necessary. According to the present 1nview, .lying each in the prolongation of the other, with or without a space occurring hetween them. if the observer would have the full benefit of such a' doubling, both fields of view must be visible from the saine eye point. `ln case the horizontal direction is the important one, as in the following will always be Sup osed, the oblong fields of View lie immediate y or with slight interval one above the other, and each object field extends along the horizon. lf each ob'ect field has to be a continuation of the other, this purpose is evidently noless attained when the middle portion of the total image occurs in. both fields of view, due to both object fields somewhat overlapping each other. If the continuation of the first object eld conie not at all in question, but that two separated object fields -are to be observed, the prescribed angular distance between the two object iields will he in general considerable. It this angle have the greatest value, 180, the observer may see, for instance, in .one field oi View what lies directly in front of hini,

.in the other what lies behind him,

Instruments, which almost conipletebv satisfy the conditionsof thefpresentinvention, are the two-fold telescopes of the wellknown coincidence telemet'ers, in which the'y `tinuity one to another.

line separating the two seinicircular fields of view lies in the directionl of the 'oase line. They require but two modifications. Firstly,

-thc adjustment niust deviate from the ordinar)Y in such a n ay that the object fields reproduced he cqualljiv high. Secondly, one of the two ob lectivo reflectors niust undergo such horizontal rotation that the two object' fields include diil'erent portions of the horizon. Besides these sniall deviations from the two-fold telescope of the coincidence teleineter, which are necessary, there are, however, greater' ones desirable for the better adaptation of the instrument to the new purpose. A large distance, for instance,

between the entrance openings of the two4 telescopes and the position of these openings in the saine horizontal .plane are no longer or" any advantage. But it may be 'eX edient to have these openings lying higher t an the ocular common to both telescopes, for in stance., in the case where onetelescope is to be used to look towards the rear. li the differenceI of level between the objectives andthe ocular be. greater than the focal length of the objectives, reversing lenses to erect the images are best to he used, inthe place of which a single one common to both telesco es can also enter. I inversely, if special jy large fields of view are to be provided, the coinnion ocular is appropriatel substituted hy two oculars,' one for each telescope, the axes of which are then so greatly inclined one to another that the requisition, that the two telescopes have a coninion eye-point, is fulfilled. Finally, the two fields of view also need no longer be two seniicircles, iorniing as a whole a full circle, but rather may appear as rectangular or elli )tical `fields.

n the annexed drawing: Figure 'l is a sec tional plan view of a two-fold telescope constructed according to the invention. Fig. 2 is a side View of this instrument.' Fig. 3 is 'the saine side view, but restricted to `the optical parts. Fig.k 4 is a sectional side view of the optical parts of another twofold telescope constructed according to the invention. L

The example represented in the three first figures is illustrative of the case', in which the two horizontal object fields are'in con- The sectional plan View in ig. l .and the side View in Fig. 2 show that no vertical axis of rotation is proequally wide apart.

y 'which it is turned. 'This arrangement being chosen, the sense is given, in which thev Va2 are arranged at diierent levels and with' an inclination of the axes relatively to each other, which inclination'is equal-'to the angle,

through which the optical construction chosen.

causes each ob'ect field to extend itself hori.,

zontally. Eac objectiveisshown to be lar-j ran ed on that side of the axis of the common ocu ar t, on which the object field lies, to

image-erecting prisms cl c2 must deviate from parallel vision. Both prisms overlap one `another with their ends, which serve 'as exit of the pencil, so'as tothe incontact in thel horizontal plane, which includes the ocular axis and from which the objective axes stand On the exit surfaces of the prisms the erected images lie, conseuently also the eventual diaphragme of the Eelde of view are to be adapted. Another reversing system can enter in the vplace of those represented, also such, in which the last reflection of the optical axis takes place in the vertical instead of thehorfizontal plane. There isnothing to prevent the union of two instruments f or two-eyed-use. This holds good also for the second example, Fig. 4. In this two-fold telescope the o ject fields lie v180 apart, one in front 'andthe other towards the rear. The instrument has its i greatest dimension in the vertical direction, so that'light from the object iield in the rear enters above the head of the observer. Terrestrial oculars, the reversing lens d of which is-coiumon, serve tore-erect the/ images, while, 1n contradistinction to the iirst example, separate eye-lenses Ye1 e2 .are arranged.

` The inverted imagesiprojected from the 0bjectives al a lie in the collective lenses f1 f2 and are oncel again reproduced through the common reversin lens d. TheseI images, now erect, lie in t le hinder collective lenses g1 g2, which form with the eye-lenses el e2 the oculars proper. While in theitelesco'pe di-4 rected towards the front two simple reflecting prisms h1 i* perform the two opposite deflections ofthe optical axis Without disturbing the erect position of the image, in the v'retrospective telescope three reflections in the vertical plane arenecessary, iii-the image is not to appear upside down. With three such refiections, however, objects in the rear would appear as viewed in a mirror,

that is to say', the right in the image would be thatlying behind the right shoulder. In order to lay the image of the restrospective telescope, as the objects would appear when the observer turned round and viewed them scopes with 'the naked eye, lateral inversion'inus't be 'provided for inthe instrument, and this can be' done by substituting a ridge. surfacefor one of 4the three simple reiiecting surfaces.

Thus. with the simple ocular prism i2 an obective prism 1h? has been combined, which latterpresents at irstva simple reflecting and 4 aiteir-igvards a ridge surfaceto the entering ra sly 'The most. suitable form for the two -fie dsof view appears to be the elliptical one.` To 'produceelhptical fields of view, the front collective lenses ffl f3 or the' hinder ones gvl'g2 or, best of all, lootli,I should be giventhis form; by doingso the short axes -would lie 'in the plane of the drawing. The entranceand-exitsurfaces of the ocular prisms "il 'i2 may then suitably receive the rectangular instead of the squarel shape, and the eyelenses el e2 would also become elliptical withv the two fields of view to a view of enablin be brought as c ose together aspossible.

The centers of the two exit pupils fall in 4the point'k of intersection of the optical axes.

I claim:

1. In a two-fold telesco e having the -entrance axes inclined to each other the combination with two objectives of two image reversing systems adaptedpto bring the images into juxtaposition in a direction approximately perpendicular to the directions. ofA the entrance axes, and an ocular system having a single eye-point.

2. Ina two-fold telescope having the entrance axes inclined to each other the combination With-two objectives of two image reversing systems adapted to bring the images' -into juxtaposition in a direction approxi- -mately perpendicular to the directions of the entrance axes, and two oculars inclined to each other` so that theireye-points coincide.

3. A two-fold telescope with the entrancel axes in the horizontal plane and inclined to each other, comprising two objectives, two terrestrial oculare having a vcommon reversing lens anda common eye-point, and two systems of relecting prisms adapted to raise] the entrance axis above the eye-point 'and to locate the images one closely above the other. 4. A two-fold telesco e with the entrance axes in the horizontal p ane, comprising two objectives, two terrestrial oculars which have a common reversing lens and a common eyepoint, and two prism systems adapted to raise the entrance axes above the eye-point,

the optical axes of the two single telescopes lying in the same vertical p ane and one prism systembeing retrospective.

ALBERT KNIG. Witnesses: l

PAUL KRUGER, Fnrrz SANDER. 

